The present invention generally relates to a modular device, system and method for storing, playing back and recording audio data. More specifically, the present invention relates to a modular device, system and method for reproducing audio data, such as voice and sound effects in a realistic manner.
It is, of course, generally known to generate simulated sounds in response to external stimuli, such as motion. One common industry in which sound production is often simulated is the model railroad industry. Sounds, such as those made by various animals, such as cows, sheep, pigs, and the like, are often reproduced. These sounds are typically generated in connection with a particular car of a railroad to enhance the interest and realism of the model railroad.
Another example of sounds being generated in conjunction with model trains is the heightened realism attained when used with a steam or diesel locomotive. In the past, when sound features have been controlled in conjunction with a model locomotive, methods other than motion have been used to turn these types of sound effects on and off. Some of these methods have been: DC voltage superimposed upon an AC voltage, magnets, reed switches or Hall effect sensors. The use of radio signals or a carrier control signal superimposed upon an AC or DC voltage have been used as well. Furthermore, a separate controller, which varies either AC or DC voltage or current, was required to control the speed and direction of the model train. There has not been a means to integrate all simulated controllable functions a model train may have into a model locomotive or car.
A need, therefore, exists to realistically reproduce and control sound effects, control model train motors and special effects. This need can be best filled by using a sound unit and Digital Command Control for controlling simulated sounds and simultaneously control propulsion of the model trains. Digital Command Control is a type of control that makes use of a digital bi-polar signal to control model trains. As defined in the NMRA Standards, the National Model Railroad Association baseline, Digital Command Control signal consists of a stream of transitions between two equal voltage levels that have opposite polarity. Alternate transitions are separate binary bits in a transmission stream. The remaining transitions divide each bit into a first part and last part. Use of this format gives the hobbyist the most choices for controlling aspects of a sound unit mounted in a model train as a self contained unit or in a track side structure as a accessory.
An example of a known sound effect producing model railroad car is described in U.S. Pat. No. 5,267,318 to Severson et al. The '318 patent teaches a speech synthesis circuit for playing selected cow voices stored as digital data in an EPROM. In a random mode of operation, a state generator provides a pseudo-random count that is used to select among four different cow voices, one of which is silence. The resulting audio output is perceived as random contented cow sounds. A pendulum motion detector provides an indication of lateral motion of the system. An up/down motion counter maintains a motion count reflecting the level of excitation of the system and the cows. The motion counter increments responsively to motion and decrements gradually in the absence of detected motion. A motion count of at least four invokes a triggered mode of operation in which the counter output is used to select among four different excited cow voices.
In the alternate embodiment of the present invention that uses only the sound reproduction apparatus, its improvement over the '318 patent is that no motion counter, micro-controller or state generator is needed to generate a response to a lateral movement of the sound car. The simple movement of the car is all that is needed to cause a response from the sound memory to play-back simple sound effects.
Previous inventions that have tried to control sound effects for model locomotives have only utilized an electro-mechanical means to control the synchronized sound functions whereas the present invention controls all aspects using digital control of the following: sound, model locomotive speed, direction and special effects on board  on-board. Another known system that relates to model trains is U.S. Pat. No. 5,174,216 to Miller et al. In the '216 patent, there is no means to execute sound effects at the model train enthusiast's discretion or to control speed, direction or other onboard  on-board special effects. The '216 patent also utilizes a single chuff sample for all speeds, that is controlled using an opto-sensor to define an on or off state. The opto-sensor simply controls one chuff sound effect no matter at what speed the model locomotive may be traveling. The speed simply determines the rate of the chuff. It cannot select from a set of speed sound effects that give a better simulation of different speeds and work loads  work-loads. The present invention overcomes this deficiency by comparing the on-off rate of the sensor to the digital speed packet. Furthermore, the '216 patent makes use of a limited menu of bell, whistle or horn sound effects that are triggered through the use of a Hall effect and various combination  combinations of magnets that are interpreted by a micro controller. The micro-controller then determines which bell/horn whistle sound effects to play. This system relies upon magnets placed along the model railway at specific points. The '216 patent system does not allow for any random play-back or variance of the predetermined menu of sound effects. The '216 patent relies upon a variable AC or DC voltage to control the frequency of the steam chuff or the amplitude of the diesel throb. The previously mentioned variable track voltage is also used to supply current to the sound reproduction circuitry. Because of the variable nature of the power supply for speed control, in order to hear sound effects through all voltage ranges especially in the 0 to 5 volt range, a switchable power supply is needed to change between the track supplied power and a battery back-up contained within the model train locomotive or car.
The '216 patent also is deficient in that it is not able to discretely control sound effects, or regulate the speed of a model locomotive, control direction and other onboard special effects at any random location. The '216 patent is only able to trigger specific sound effects at predetermined locations, and a battery back-up is required for use in all voltage ranges. Because the '216 patent makes use of the variable track supplied power to supply voltage for the circuitry and regulation of the chuff or diesel sound effects, it is unable to operate at slow prototype speeds in a model setting.
There have been attempts at controlling the speed of a model locomotive, sound and special effects to overcome the above deficiencies. One known system that attempted to do this is taught in U.S. Pat. No. 4,914,431. In this patent, the motor controller device is used with AC-powered model trains where typically these types of trains make use of variable AC voltage to control the speed of a locomotive, typically described as “Lionel trains.” Furthermore, these types of trains make use of a three-position switch that is controlled by a solenoid to determine forward, neutral or reverse. This unit is called a reverse unit, which the '431 patent is designed to operate exclusively. The scope of the '431 patent is intended to sync the electronic reverse units of a master and slave locomotive. Furthermore, the control system uses state generators for expansion of the remote control effects found on a model locomotive. This is accomplished by simply using a positive and or negative DC digital pulse repeatedly applied to create and to control a plurality of state control signals. Although each motor controller can operate up to sixteen states, only four state generators are enabled for use. This pulse signal is superimposed on the AC motor control supply voltage and can only control one set of special effects per usage. Another deficiency of the '431 patent is that, in its preferred embodiment, only two addresses are possible: a master and a slave. The '431 patent is not designed for multiple locomotives in use in multiple combinations. For the operator of DC powered trains, these deficiencies make the device unsuitable. Finally, this system to control motors and sound effects is a proprietary system and does not inter-operate with any control system other than those for AC-powered trains.
Another known patent that attempts to control speed, sound and special effects in more than two locomotives is U.S. Pat. No. 5,441,223 to Young. In this patent, an RF and an electro-magnetic signal are used in conjunction with a triac to control speed of AC powered locomotives. The triac is modulated and turns the AC power on and off for speed control of the addressed locomotive. This system is designed specifically for “Lionel” brand trains. Reverse compatibility is required to operate previously made AC trains that use the three position reverse unit. As in the '431 patent, the '223 patent uses a switching circuit to control the reverse unit using commands. In a further attempt to preserve reverse compatibility, the '223 patent may still superimpose upon the AC motor control current a DC offset for control of whistle and bell effects on non-receiver equipped locomotives. Due to the need to control the reverse unit and the DC offset, any other type of model trains, that require DC current for motor power cannot use this system. In addition, to the limitation of operating AC powered trains only, the quantity of locomotives the hobbyist may operate with this system is limited to ten. There are additional operational limitations to this system: it requires a hands on approach to access a switch, to place the locomotive in a programming mode, a manual switch needs to be accessed, the inability to tailor locomotive motor performance characteristics such as acceleration and/or deceleration, and the inability to tailor sound performance to personal preferences.
There are also three other known U.S. patents that make use of a command control structure for only motor control. One is U.S. Pat. No. 4,572,996 to Hanschke et al. This patent makes use of a Digital Command Control format, but is limited in scope due to its limited address capabilities and the lack of hobbyist programmable features to enhance performance of the locomotives and sound systems. Like the '431 and '223 patents, it is a proprietary system that uses its own protocol. Furthermore, the '996 patent lacks the ability to operate other brands of Digital Command Control receivers which limits it usage.
U.S. Pat. No. 4,335,381 to Palmer makes use of a composite waveform, again demonstrating the proprietary nature of these types of controls. Furthermore, the data portion is a hurst that is attached to the back of the waveform that actually powers the devices attached to the controller. This system, although flexible, appears to be limited in its address capabilities due to the method of selecting addresses for each receiver, and the quantity of data bits appears to affect the amount of power available to power motors and ancillary devices. Like the '996 patent, it is limited in its preferred embodiment to speed, direction and inertia.
U.S. Pat. No. 4,341,982 to Lahti et al. makes use of a carrier control signal. This patent uses DC power for propulsion of the model locomotive motor and simply superimposes a selected modulated frequency on top of the DC power. The superimposed control signal is a band width  band-width equal to the highest frequency of the carrier control signal which is equal to the highest selected carrier control address. This system's deficiencies include no easy way to change a locomotives address, limited in band width  band-width for address range, operating characteristics of the motor controller are limited to: direction and deceleration only, and no provisions for additional features to be actuated remotely, such as operation of a sound unit or special lighting effects.
As seen by the above patents, prior art exists; however, each makes use of a proprietary format that only operates each manufacturer's or inventor's devices and are limited in operational characteristics. The present invention, on the contrary, operates across any manufacturer's control systems as long they observe the NMRA digital format now in practice.
The present invention overcomes the above shortcomings by utilizing a micro-controller that decodes a discreet bi-polar digital command directed to its specific address for control of: sound effects, speed regulation, direction of a model locomotive and control of on-board special effects. In addition, the constant voltage supplied to the track is able to supply a constant voltage from a regulated power source to the present invention at all times, no matter what the speed of the model locomotive. In addition to the simple features as outlined, the hobbyist also has access to certain registers that may be used to customize a model locomotive's motor control characteristics and sound features.
The previously mentioned micro-controller uses, in this embodiment, a prescribed packet format that includes speed, direction and accessory/special effects commands. The preferred digital format that is used is dictated by the National Model Railroad Association. By using this format the present invention is able to inter-operate with control systems that are currently on the market and is not dependent on a proprietary control system. However, various digital formats exist for the use of model train control, and the present invention can be adapted to these as well. All aspects of the present invention may be controlled in a “hands-off” manner by executing various addressed commands that are sent on a plurality of tracks as a digital signal to a specific model locomotive. The only limit on this type of invention is the size of the micro-controller and sound memory.